Let-off mechanism for looms



R. GLASER.

LET-OFF MECHANISM FOR LOOMS.

APPLlcATioN FILED SEPT. a, 1920.

INVENTOR W/TA/ESSES uoaLpH GLASS# A TTHNE YS I .y IHM.

m Tt ad LET-GFF MECHANISJL FOR LOOMS.

Application filed. September To all cli/1.0m t may conce/m.'

3c it known that l, RUDoLrH Gnasnn, a citizen of the United States. and a resident of Haledon7 in the county of Passaic and State of New Jersey, have invented a nen' and Improved Let-Off Mechanism for Looms, of which the following is a full, clear, and exact description.

This invention relates to looms and has particular reference to an improvement in let-off mechanisms or tensioning devices for the Warp beams thereof.

The invention contemplates broadly, the provision of an automatic let-off mechanism which operates to insure a constant and even tension on the Warp threads under all Working conditions of the loom.

Another object of the invention resides in the provision of an automatic let-ofil mechanism which functions With equal elficiency irrespective of the Weight of the material which is being operated upon.

A further object in vieuv is to produce a device ofthe character described.y which is constructed and operates to maintain at .all times an even tension on the Warp threads Whether the mechanism is in the act of performing its function or at rest. l

A still further object accomplished by the invention lies in the provision of a device of this class which includes the features of adjustability, simplicity, eiliciency. and cheapness of production, installation and up-lreep.

With the aboverecited and other objects in view, some of which will appear hereafter as the nature, purpose and operation of the device is more clearly set forth in the following detail description, and the appended claims, reference is made to thc accompanying drawing, in which:

The figure is a fragmentary side elevation of a portion of a loom illustrating the same equipped with the let-olf mechanism.

Referringto vthe drawings by characters of reference, 10 designates a portion of the frame Work ofa loom which is provided with angularly disposed brackets 11, the outer extremity of Which is mounted for rotation on the trunnions 12, a Warp beam 13 upon which the supply of Warp threads 14 are Wound and from which the same are fed into the loom is provided and is of the usual construction.

The automatic let-olf mechanism consti,-

Speccation of Letters Patent.

Patented May 2, 1922.

3, 192e. Serial No. 407,879.

tuting the invention comprises a friction bralre band 15 connectedyat one extremity to a stud 16 supported from one of the brackets 11 and at its opposite extremity to a Weight arm 17 which is pivoted to the stud 16 at one end and provided at its opposite end with a vertical aperture 18. The intermediatc portion of the brake band encircles and operates in a Igroove 19 provided in one or both end anges of the Warp beam and functions When the Weight arm 17 gravitates under it ovm Weight, to frictionally retard the rotation of the Warp beam during the feeding of the Warp threads 14 into the loom. In order to provide means to relieve the Warp beam of the frictional retarding action of the brake band 15 when the tension on the Warp threads becomes eX- cessive, use is made of an automatic compensating apparatus which comprises the rock levers 2O fulcrumed between their opposite extremities as at 21 to a cross shaft. The inner extremities of the levers 20 are connected by a transverse guide bar or roller 22 over which the Warp threads are trained from a guide' bar or roller 23 arranged transversely of the yframe of the loom.

F rom the guide bar 22 the Warp threads are trained around a, second guide bar or roller 211 arranged transversely of the loom frame. The opposite extremities of the rock levers 2O are connected by cross rod 25 and a second cross rod 26 is arranged transversely and connects the rock levers between the' fulcrum and the outer extremities thereof. A vertical rod 27 is suspendedy from the cross rod 26 and the free threaded extremity 28 thereof passes through the vertical aperture 18 in the free end of the weight arm 17. A stop nut 29 is vertically adjustable on the threaded extremity 28 ofy the lift rod. Y

In operation of the let-ofil mechanism, a Weight 30 of the desired size is arranged on the cross rod'25 connecting the free outer extremities of the rock lever. As the Warp threads 111 are fed from the Warp beam, the Weight 80 will function to lift the inner ends of the levers 20 simultaneously lowering the lift rod 27 and disengagingthe stop nut 29 to permit the Weight of the arm 17 to retard the revolutions of the Warp beam suiciently to obtain the proper tension on the warp threads. Should the tension on the Warp threads become excessive, a pull will rei be exerted on the inner end of the levers 20 by the portion of the warp threads trained thereover, thereby lifting the outer ends ot the levers against the action ot the weight 30, thus resulting in an upward movement of the lift rod 27 and the consequent engagement of the stop nut 29 with the weighted arm. lllhen the arm 17 is lifted the retarding action of the friction brake band l5 will be relieved and operate to permit free revolution of the warp beam until the tension is slightly in excess or the weight carried by the outer extremities oi' the rock lever. lit has been observed by practical demonstration that the letbff mechanism tunetions to maintain an even tension on the warp threads at all times, irrespective of whether the clutch band l5 or the weight 30 is functioning or whether the parts are in actual operation. By employing a heavier weight 30 and adding weights to the weight arm 17, the mechanism will function with equal eiiiciency on heavier material and it is therefore obvious that the mechanism may be employed for any grade of work.

`While there has been illustrated and described a single and preferred form of the invention, it is to be understood that the right is reserved to embodiments other than those actually shown, to the ull extent indicated by the general meaning of the terms in which the claims are expressed and by -changes in the phraseology of the same.

Having thus described my invention, l claim as new and desire to secure by Letters Patent:

1. lin an automatic let-off mechanism ior looms, the combination with the warp beam of the loom, of a weight arm having pivotal connection at one end with the warp beam support, a rictional brake band encircling the warp beam and having connection at its opposite ends with the support and the weight arm at its pivotal point whereby the weight of the arm when free to move will serve to eiect contraction of the band about the beam to constitute a brake for retarding its rotation, pivoted means over which the warp threads are guided from the warp beam, an adjustable connection with the tree extremity o]a the weight arm for rendering `said' arm inactive when tension of the warp threads become excessive, and means carried by said pivoted means for regulating the amount ot tension on the warp threads re- `quired to render the weight arm inactive.

2. In an automatic letlo'lt1 mechanism for looms, the combination with the warp beam thereof, of a weight arm pivoted at one exvtremity to the warp beam support and pro- ,eve

vided with a constricted aperture in its opposite extremity, a friction brake band encircling the warp `beam and having connection at its opposite ends irrespectively with the support and the weight arm at its pivot whereby the weight of said arm when tree to move will serve to eiect contraction of the brake band about the beam to produce a braking action for retarding the rotation thereot, a rock lever pivoted between its ends to the loom frame in superposed relation to the weight arm and having a thread `nido at one extremity over which lthe threads leading from the warp beam are trained, a litt rod connected to the rock lever on the opposite side of the pivot from the thread guide supporting extremity, the lower end oi said lift rod being threaded and freelyy received through the constrieted aperture in the warp arm, a nut mounted on said threaded extremity constituting an adjustable stop adapted to coact with the under side ot the tree extremity of the weight arm when excessive tension of the warp threads extending through the thread giiiide operate to exert a downward pull on the lever, and means provided on the rock lever at the opposite extremity from which the thread guide is supported for accommodating various weights whereby to regulate the amount ci tension necessary to litt the weight arm.

3. ln an automatic let-off mechanism for looms, the combination with the warp beam, oi a weight arm pivoted at one extremity to the warp beam support and provided with an aperture in its opposite extremity, a 'rietion brake band encircling the warp beam and having connection at its opposite ends with the support and the weight arm adjacent its pivot whereby the weight ot' the arm when tree to move willserve to eiiect contraction of the brake band about the beam to retard the rotation thereoa rocklever pivoted to the loom frame and having a thread guide at one extremity over which the threads leading from the .beamnare trained, a weight supported by the lopposite extremity ot the rock lever, a lift rod connected to the weight arm of the rock lever adjacent its pivot, the lower end of said lift rod adapted to be freely received through the aperure in the weight arm, and an adir-.stable stop carried by the lower end thereot and adapted to coact with the tree extremity of the weight arm when excessive tension of the warp threads actuate the rock lever whereby the weight arm is rendered inactive.

@LASER 

